Field of Invention
Scissors-type cutting device.
The cutting action of standard scissors requires specific movements of the thumb and one or more fingers. The standard scissors referred to herein are those scissors that have loops at the handle end portion for engaging the thumb and one or more fingers. The cutting blades of standard scissors, which are on the opposite ends of the finger and thumb engaging loops, are activated for cutting by the movement of the thumb and finger(s) which move the blades alternately together and apart around a pivot point at which the blades are movably connected.
This cutting action of standard scissors requires the operator to squeeze the loops together with the finger(s) and thumb in their respective loops and then to contract the muscles of the finger(s) and thumb to reopen the blades. Specific gross motor skills are required for operating such standard scissors. Additionally, the operator must have fingers and a thumb capable of the required movements.
People with physical defects of either the fingers or the thumb and people with neurological disorders adversely affecting their ability to perform the required gross motor movements find it awkward, inconvenient, or impossible to use standard scissors. This includes, but is not limited to, those persons handicapped by cerebral palsy, radial club hand deficiency, arthritis, stroke, spinal meningitis, and by physical injury. Thus, a substantial number of people are unable to use standard scissors.
In addition to being unusable by a significant number of handicapped persons, standard scissors have other shortcomings. For example, it is difficult and cumbersome to use standard scissors to cut stiff materials. When used to cut a stiff material, it is necessary to bend the material to permit not only the scissors but also the hand operating the scissors to pass through the material as it is being cut.
Additionally, the use of standard scissors generally requires the user to hold the hand at an right angle relative to the wrist. This is a less comfortable position than having the hand in its natural position in a straight line from the wrist. Scissors which could be used with the hand in its natural position extending in a straight line from the wrist would be more comfortable and easier to use for all users and especially users having handicaps as discussed above.
Finally, standard scissors generally are made with the finger engaging loop or both finger and thumb engaging loops having surfaces that are inclined at an angle to accommodate only right-handed persons. While scissors having loops with surfaces inclined to accommodate left-handed persons are available, they are not as widely available as right-handed scissors.
Despite the limitations of standard scissors, few alternatives are available. One alternative is disclosed in U.S. Pat. No. 4,663,848 to Sell. In Sell, the finger and thumb engaging loops of the standard scissors are replaced with a ball-shaped elastic member and a spring mechanism that biases the blades toward the open position. When the ball-shaped member is squeezed, the scissor blades are pushed together for cutting. The spring mechanism returns the blades to the open position.
The device disclosed in Sell requires a complex construction for the scissors handle and also requires certain motor movements and dexterity for holding and squeezing the ball. Furthermore, the device disclosed in Sell, like standard scissors, requires the user to hold the hand at an angle relative to the wrist. Finally, the devise disclosed in Sell does not solve the problems associated with using scissors to cut stiff materials. Accordingly, the device disclosed in Sell does not solve all of the significant shortcomings associated with standard scissors leaving considerable room for improvement in the construction of scissors.